DSA-1730-1 proftpd-dfsg -- SQL injection vulnerabilites

The security update for proftpd-dfsg in DSA-1727-1 caused a regression
with the postgresql backend. This update corrects the flaw. Also it was
discovered that the oldstable distribution (etch) is not affected by the
security issues. For reference the original advisory follows.

Two SQL injection vulnerabilities have been found in proftpd, a
virtual-hosting FTP daemon. The Common Vulnerabilities and Exposures
project identifies the following problems: